The Times-Picayune graphicScientsts believe this is what the Louisiana coast could look like by 2100 if coastal areas are not restored and elevated as sea level rises.

The final draft of a long-delayed Army Corps of Engineers study on how to protect New Orleans and other populous areas of Louisiana's coastline from catastrophic hurricanes remains deeply flawed, experts who reviewed the study for the corps said on Friday.

The biggest problem continues to be the corps' failure to recommend a single statewide list of hurricane-protection projects to Congress for authorization, rather than five regional plans offering a multitude of options, the scientists and engineers said during Tulane University's 2010 Engineering Forum.

"They just provided a menu (of a half-dozen sets of projects for each region) and stopped, expecting Congress to choose the right one," he said.

In the aftermath of Hurricane Katrina, Congress ordered the corps to provide it with the study outlining a plan for protecting New Orleans and other coastal communities from the effects of "the equivalent of a Category 5" hurricane.

The nearly 8,000-page Louisiana Coastal Protection and Restoration Study was supposed to have been submitted to Congress by December 31, 2007, but is being held in the office of Assistant Secretary of the Army Jo-Ellen Darcy.

The draft estimates the cost of providing protection to the state's coast at between $70 billion and $136 billion. Included are five or six lengthy lists of alternatives for each of five regions of the state's coastline.

In the New Orleans area, the alternatives include much higher levees along existing levee alignments and extended north into St. Tammany Parish, a variety of gate alternatives for the Chef Menteur and Rigolets passes into Lake Pontchartrain, and proposals to either relocate or buy out homes and businesses in areas at greatest risk of surge flooding.

Areas with higher populations, such as New Orleans, could be protected from either a "modest" Category 5 hurricane -- a so-called 400-year storm that would have a 0.25 percent chance of occuring in any year and cause surge similar to that created by Katrina on the Mississippi coastline -- or a much stronger Category 5 hurricane -- a 1,000-year storm with a 0.1 percent chance of occuring in any year, according to the study.

Areas with smaller populations might be provided with protection from surge created by a hurricane with a 1 percent chance of occurring in any year, a so-called 100-year storm, which would be similar in size to Hurricane Rita in 2005 or Gustav in 2008.

The draft included a recommendation of as much as three years further study that would lead to a winnowing of alternatives, with individual projects then to be presented to Congress under existing authorizations, such as the Lake Pontchartrain and Vicinity levee project that includes hurricane levees on the east bank, or the Louisiana Coastal Area Ecosystem Restoration program, which includes diversions and wetlands restoration projects.

Dahrlymple said another "fatal flaw" of the corps study was its failure to detail what Louisiana's future coastline should look like, in light of the continuing loss of 24 square miles of wetlands along the coast each year and the fact that the Mississippi River carries only half the land-building sediment it did 100 years ago.

"This (the rate of wetlands loss) has been going on for 80 years or better, yet the Corps of Engineers has as the premise of their entire report that the shoreline of the state of Louisiana will be maintained in place, that is, what we have now is what we'll have in the future," he said.

"There are plenty of other authorities besides us that say this is a fool's errand," he said. "You've been losing 24 square miles a year for a very, very long time, and it's not clear how you're going to stop that."

That recommendation tracks a 2006 National Research Council report aptly titled "Drawing Louisiana's New Map," which also concluded that state and federal officials must identify which areas of the coastline are sustainable before choosing which restoration projects to build.

The LACPR peer review committee recommended that the corps must come up with a budget for using the sediment and water carried by the river as part of its comprehensive plan in two reports, the first following the release of an initial draft of the corps study in 2008, and the second after the most recent draft was released in 2009.

The corps has agreed to develop such a budget, but has said it won't be complete until July, Dahlrymple said.

John Boland, another committee member who also is an engineering professor at Johns Hopkins, said the corps also failed in its efforts to create a "multicriteria decision analysis" to weigh the positives and negatives of individual strategies, including construction of higher levees and gates, rebuilding wetlands and coastlines, and moving or buying out residents in the most vulnerable areas.

The corps study was extremely complex, Boland said, with thousands of individual projects first winnowed down to 111 individual plans spread out over the five planning districts.

But the corps' first effort at weighting projects and plans against each other was flawed by basing it on input from only those "stakeholders" who attended several meetings held across the state to identify what issues should be considered most important, Boland said.

At that first meeting, the stakeholders weren't told what projects were being considered, so they had no way of determining the importance of the individual characteristics they were asked to rate -- fisheries, shipping, flood insurance costs, etc. -- to the projects that the corps was studying, he said.

When the peer review committee pointed out such problems, the corps didn't throw out its earlier results. It instead made those results a single factor in a new list of factors they chose to weigh individual projects.

The ultimate weighting system still failed to consider a variety of values that are difficult to measure, Boland said. For instance, in comparing the use of a ring levee around a small community against elevating all of the community's buildings above potential storm surge levels, "nothing in the metrics captured the cost and inconvenience to residents of having to elevate their homes and then living that way," he said.

The corps has said the failure of the winnowing process is a key reason why it is recommending in its draft that Congress give it several more years to determine the best projects for each segment of the coast.

The study also is flawed in addressing storm surge risk only in areas south of Interstates 10 and 12, said John Christian, another panel member who is a retired senior vice president of the Stone & Webster engineering firm.

"I'm not sure the surge water is aware it is supposed to occur only south of I-10," he said, adding that the study should have included Baton Rouge and upper areas of the Atchafalaya River.